Systems and methods for providing heat to a catalyst of an after-treatment system

ABSTRACT

Methods and system are provided to heat a catalyst of an after-treatment system for a vehicle. The after-treatment system comprises a heating module having a plurality of heating elements. Each of the plurality of heating elements is independently operable to provide thermal energy to the catalyst of the after-treatment system. One or more of the heating elements of the heating module are selectively operated to provide heat to the catalyst based on an operational parameter of the after-treatment system.

BACKGROUND

The present disclosure relates to systems and methods for controlling aheating element for providing heat to a catalyst of an after-treatmentsystem, more particularly, but not exclusively, to systems and methodsfor selectively operating a heating module of an after-treatment systemof a hybrid vehicle to improve hybrid battery durability.

SUMMARY

Through consumer demand and local regulation, the need for reducedengine emissions has led to engine exhaust systems that comprisecatalytic converters. Catalytic converters are a specific type of engineafter-treatment system that reduces pollutants in exhaust gases bycatalyzing a redox reaction. Catalytic converters are located downstreamof the engine within a structure/housing in the exhaust system, that isdesigned to contain and direct exhaust gases over and/or through thecatalytic converter. Like many after-treatment systems, catalyticconverters require heating up to be most effective. As the demand forcleaner emissions increases and legislation requires a reduction in thepollutants produced by internal combustion engines, solutions involvingexhaust after-treatment systems are increasingly desired.

According to examples in accordance with an aspect of the disclosure,there is provided a method of providing heat to a catalyst of anafter-treatment system, e.g., of a vehicle. The after-treatment systemcomprises a heating module having a plurality of heating elements. Eachof the plurality of heating elements is independently operable toprovide thermal energy to the catalyst of the after-treatment system.The method comprises selectively operating one or more of the heatingelements of the heating module to provide heat to the catalyst based onone or more operational parameters of the after-treatment system and/orthe vehicle.

In some examples, the method further comprises determining how many ofthe plurality of heating elements to selectively operate to achieve athreshold temperature of the catalyst, e.g., an optimum operatingtemperature of the catalyst. For example, it may be determined that tomeet the threshold temperature, all of the heating elements will need tobe operated. In some examples, it may be determined that to meet thethreshold temperature, a subset of the plurality of heating elementswill need to be operated. In some examples, the threshold temperature ofthe catalyst is achieved within a time threshold. For example, a timethreshold may be set as a limiting period in which the catalyst shouldachieve the threshold temperature. In this way, more heating elements ofthe heating module may be selectively operated to meet both thethreshold temperature and the time threshold. In some examples, inresponse to determining that the threshold temperature has beenachieved, one or more, e.g., a subset, of the plurality of heatingelements of the after-treatment system may be deactivated.

In some examples, the one or more operational parameters comprise atleast one of a energy throughput of a battery, an engine temperature, anexhaust gas flow-rate through the after-treatment system, a thermalenergy output from each of the plurality of heating elements, a maximumthermal energy output from the plurality of heating elements, and/or anamount of particulate matter in the after-treatment system. Energythroughput is the total amount of energy a battery can be expected tostore and discharge over its lifetime. In some examples, the energythroughput may be associated with an energy usage profile of an HEVbattery.

In some examples, the method further comprising determining one or morecontextual factors, wherein the one or more contextual factors compriseat least one of an ambient temperature, a state of charge of a powersource of the vehicle (e.g., a hybrid vehicle battery), a time since alast engine start-up, and/or a delta temperature between the temperatureof the after-treatment system and the ambient temperature. In someexamples, at least one of the plurality of heating elements of theheating module is selectively operated to provide heat to the catalystbased on one or more of the contextual factors.

In some examples, the method further comprises starting an engine of thevehicle after the after-treatment system reaches the thresholdtemperature. In some examples, the method further comprises starting theengine based on the one or more contextual factors. In some examples,the method further comprises starting the engine based on the one ormore operational parameters. For example, the engine start-up proceduremay be altered based on the one or more contextual factors and/or theone or more operational parameters.

According to a second example in accordance with an aspect of thedisclosure, there is provided an after-treatment system comprising aheating module. The heating module comprises a plurality of heatingelements, wherein each of the plurality of heating elements isindependently activatable to provide thermal energy to a catalyst of theafter-treatment system.

In some examples, each of the plurality of heating elements has the samethermal output power. For example, each of the plurality of heatingelements may have 2 kW (2000 Watts) of thermal output. In some examples,each of the plurality of heating elements has a different thermal outputpower. For example, a first heating element may have 1 kW of thermaloutput and a second heating element may have 3 kW of thermal output. Itshould be understood that the aforementioned values of thermal outputpower and the number of heating elements are merely intended asillustrative and are non-limiting, and that other values of thermaloutput power may also be used and are intended to fall within thepresent disclosure. For example, there may be a total of ten heatingelements of 400 W (400 Watts) of thermal output or five heating elementsof various thermal output totaling 4 kW (4000 Watts) of thermal output.In some examples, the total amount of thermal output of the plurality ofheating elements of the heating module may vary for any given catalystbased on the one or more contextual factors or the one or moreoperational parameters.

In some examples, the plurality of heating elements are spatiallyseparated, e.g., within the heating module. For example, the heatingelements may be concentric coils occupying the same spatial regionwithin the heating module, but each heating element may be spatiallyseparated from the next heating element within that region. In someexamples, the plurality of heating elements occupy the same spatialregion and are electrically insulated from one another. For example, theheating elements may be different portions of a metallic foam (e.g., ofunitary structure) that are electrically isolated from each other. Insome examples, the heating module of the after-treatment system isconnected to a high voltage power source, e.g., a power source of ahybrid electric vehicle (HEV) such as a hybrid battery.

According to a third example in accordance with an aspect of thedisclosure, there is provided a vehicle. The vehicle comprises anafter-treatment system. The after-treatment system comprising a heatingmodule comprising a plurality of heating elements, wherein each of theplurality of heating elements is independently activatable to providethermal energy to a catalyst of the after-treatment system.

According to a fourth example in accordance with an aspect of thedisclosure, there is provided a non-transitory computer-readable mediumhaving instructions encoded thereon for carrying out a method to provideheat to a catalyst of an after-treatment system for a vehicle, theafter-treatment system comprising a heating module having a plurality ofheating elements, wherein each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system, the method comprising selectively operating oneor more of the heating elements of the heating module to provide heat tothe catalyst based on an operational parameter of the after-treatmentsystem.

For the avoidance of doubt, the system and methods for providing heat toa catalyst of an after-treatment system for a vehicle, according to anyof the examples described herein, may be used to improve the emissionsof a vehicle. Whilst the benefits of the systems and method may bedescribed by reference to hybrid vehicles, it is understood that thebenefits of the present disclosure are not limited to such types ofvehicle, and may also apply to other types of vehicles, such asforklifts, trucks, buses, locomotives, motorcycles, aircraft andwatercraft, and/or non-vehicle based systems that utilize a catalyticconverter, such as electrical generators, mining equipment, stoves, andgas heaters.

These examples and other aspects of the disclosure will be apparent andelucidated with reference to the example(s) described hereinafter. Itshould also be appreciated that particular combinations of the variousexamples and features described above and below are often illustrativeand any other possible combination of such examples and features arealso intended, notwithstanding those combinations that are clearlyintended as mutually exclusive.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the disclosures hereinwill be apparent upon consideration of the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein.

FIG. 2 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein.

FIG. 3 illustrates the PWM switching of a hybrid system without theteachings of the present disclosure.

FIGS. 4A to 4C illustrate exemplary heating elements of a heating modulefor providing heat to a catalyst of an after-treatment system, inaccordance with at least one of the examples described herein.

FIGS. 5A and 5B depict exemplary results achieved due to theimplementation of the present disclosure, with respect to a hybridbattery, in accordance with at least one of the examples describedherein.

FIG. 6 illustrates an exemplary exhaust system comprising anafter-treatment system, in accordance with at least one of the examplesdescribed herein.

FIG. 7 illustrates an electrical power control system for a hybridvehicle, in accordance with at least one of the examples describedherein.

FIGS. 8 to 10 illustrate example flow charts of a method of providingheat to a catalyst of an after-treatment system for a vehicle, inaccordance with at least one of the examples described herein.

FIG. 11 illustrates a vehicle comprising an engine and an exemplaryexhaust system, in accordance with at least one of the examplesdescribed herein.

FIG. 12 illustrates a block diagram of a computing module, in accordancewith some embodiments of the disclosure.

DETAILED DESCRIPTION

It should be understood that the detailed description and specificexamples herein, while indicating exemplary embodiments, are intendedfor purposes of illustration only and are not intended to limit thescope of the disclosure. These and other features, aspects, andadvantages of the present disclosure will become better understood fromthe following description, appended claims, and accompanying drawings.It should be understood that the Figures are merely schematic and arenot drawn to scale. It should also be understood that the same orsimilar reference numerals are used throughout the Figures to indicatethe same or similar parts.

As discussed briefly above, current regulations on emissions standardsare requiring manufacturers of internal combustion engines to reduce theoperating emissions from the engines they manufacture. These engines areused in any appropriate type of vehicle, such as an automobile, amotorbike, a marine vessel, or an aircraft. In particular, the vehiclemay be any appropriate type of hybrid vehicle, such as a Hybrid ElectricVehicle (HEV), a Plug-in Hybrid Electric Vehicle (PHEV), a Mild HybridElectric Vehicle (mHEV), or any other vehicle having an engine and anelectrified powertrain. Typically, hybrid vehicles use two or moredistinct types of means to store energy, such as batteries to storeelectrical energy and gasoline/diesel to store chemical energy. Thebasic principle of hybrid vehicles is that the different types of motorshave diverse efficiencies under different conditions, such as top speed,torque, or acceleration and therefore switching from one type of motorto another yields greater efficiencies than either one could have theirown. However, under the proposed new emissions standards in markets suchas the European Union (EU), North America, and the United Kingdom (UK),the increased efficiencies of hybrid vehicles may be insufficient tosatisfy new emission standards.

One solution to reduce the toxic emissions of vehicles is the use of anexhaust after-treatment system. Exhaust after-treatment systems aim toreduce hydrocarbons, carbon monoxide, nitrous oxide, particulate matter,sulfur oxide, and volatile organic compounds such aschlorofluorocarbons. Examples of exhaust after-treatment systems includeair injection (or secondary air injection), exhaust gas recirculation,and catalytic converters.

Electrically heated catalysts, or eCATs, are a type of catalyticconverter, which have been in use for a number of years. An eCATtypically comprises a heating element disposed within, or near to, acatalyst. eCATs are required in various use cases and will demand apower supply between 0-4 kW (0 to 4000 Watts) for example, depending onthe use case. For example, the heating elements within the eCATs willhave a thermal output of 0-4 kW (0 to 4000 Watts). An eCAT typically haslow inductance and therefore the power consumption can be changedrapidly. The eCAT demand is supported by a hybrid powertrain electricalsystem in an HEV, mHEV, or PHEV platform. For example, in a cold startuse case, the eCAT will demand am eCAT rated power (e.g., ˜4 kW) tomaintain aftertreatment temperature. In some examples, the power controlmodule (PCM) demands the eCAT rated power from the HEV system for ˜200seconds. This load will be supported by the hybrid battery transientlyuntil the e-machine can respond to support the load. However, in someuse cases in which the e-machine can't support the total demand, thebattery will need to support the eCAT power supply.

In some examples, the eCAT will be required to perform a heatmaintenance use case. To support the intermediate power levels for a‘heat maintenance’ use case, a power (e.g., ˜2 kW) less than the ratedpower (e.g., ˜4 kW) of the device may be required. For example, thehybrid battery of the HEV system will be switched on (4 kW) and off (0kW) through Pulse Width Modulation (PWM) to generate an average 2 kWpower supply, as will be described in more detail with regard to FIG. 3. This cycling of the battery will increase the battery energythroughput, aging the battery.

Accordingly, in some examples, an after-treatment system comprising acatalyst and a plurality of heating elements of a heating module isdisclosed, as is described in more detail below. The after-treatmentsystem comprises a heating module comprising a plurality of heatingelements, wherein each element of the plurality of heating elements areable to be selectively operated. For example, each heating element maybe activated and/or deactivated separately. In this way, each heatingelement could have a lower power consumption than the maximum powerrequired to support the worst-case use case (e.g., a cold start use caseat ˜4 kW demand as mentioned previously). In some examples, in a totalactivation approach, wherein all of the plurality of the heatingelements are selectively operated, the maximum power demand could stillbe satisfied to support the worst-case use case power demand. In someexamples, in an intermediate power demand use case, such as ‘heatmaintenance’, any number, e.g., some, of the plurality of heatingelements could be selectively activated to satisfy the power demand tomeet catalyst light-off In one example with two heating elements, eachelement could be rated at 2 kW power, and therefore only one of theelements would be required to satisfy the power demand for the ‘heatingmaintenance’ case. This approach is advantageous, as the PWM switchingapproach would no longer be required and, consequently, the energythroughput and impact on battery life would be reduced, e.g., as shownin more detail with regard to FIGS. 5A and 5B.

In particular, the systems and methods described herein may be used toaddress the light-off procedure of a catalyst in an eCAT of hybridvehicles, and/or to increase the life of the battery of the hybridvehicle, e.g., by minimizing the HEV battery energy throughout duringeCAT use; and further limit the degradation in its discharge and chargeperformance over its life, e.g., by reducing the energy throughput andinternal resistance increase over usage. For the avoidance of doubt, anyof, or at least any part of, the system architectures described belowmay be implemented in any appropriate hybrid vehicle, and are notlimited to implementation in any one type of hybrid vehicle.

FIG. 1 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein. In some examples,the after-treatment system comprises a heating module having a pluralityof heating elements. Each of the plurality of heating elements isindependently operable, e.g., controllable, activatable and/ordeactivatable, to provide thermal energy to the catalyst of theafter-treatment system. Process 100 starts at step 102 where one or moreheating elements of the heating module are selectively operated. Forexample, one or some of the plurality of the heating elements may bemore desirable to selectively operate than one or more other heatingelements, e.g., based on achieving the target after-treatmenttemperature threshold with the minimum increase in HEV battery energythroughput, thermal output and/or proximity to the catalyst.

At step 104, heat is provided to the catalyst based on an operationalparameter of the after-treatment system using one or more heatingelements of the heating module. In some examples, the operationalparameter is an operational parameter of the after-treatment system. Insome examples process 100, comprises a step of selectively operating oneor more of the heating elements of the heating module to provide heat tothe catalyst based on one or more operational parameters of theafter-treatment system. However, the method may comprise a plurality,e.g., two steps. In this way, the order of the steps in FIG. 1 is forillustrative purposes and, in some examples, step 104 may precede 102.

In some examples, the one or more operational parameters comprise atleast one of an engine temperature; an exhaust gas flow rate through theafter-treatment system; a maximum thermal energy output from theplurality of heating elements; and/or an amount of particulate matter inthe after-treatment system. For example, if the ambient temperature ofthe environment of the after-treatment system is very low, more thermalenergy may be needed to be supplied to the heating element to ensurethat the after-treatment system is sufficiently preheated.

In some examples, providing heat to the catalyst of the after-treatmentsystem may be reliant, at least in part, upon airflow passing over theheating element to transfer the thermal energy to the catalyst and toprotect the element from overheating. Therefore, before engine start andthus without the exhaust gas flow of a running engine, a pump may beadded to the system to enable the transfer of thermal energy from theeCAT to the catalyst by generating airflow in the exhaust to transferthe thermal energy from the heating element to the catalyst. In someexamples, this may include adding a pump to the exhaust gas recovery(EGR) circuit or utilizing (or repurposing) an e-compressor of thevehicle.

FIG. 2 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein. In some examples,the after-treatment system comprises a heating module having a pluralityof heating elements. Each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system. Process 200 starts at step 202, a decision ismade on whether or not an operational parameter has been determined. Inresponse to step 202, process 200 continues to step 204 if the answer tostep 202 is no. At step 204, an operational parameter of theafter-treatment system is determined. Operational parameters arevariables linked to the exhaust after-treatment system or the engine asa whole. For example, battery energy throughput, an engine temperature,an exhaust gas flow-rate through the after-treatment system, a maximumthermal energy output from the plurality of heating elements, or anamount of particulate matter in the after-treatment system. If theanswer to step 202 is yes and an operational parameter has beendetermined, or after step 204 has been completed, process 200 continuesto step 206. Energy throughput is the total amount of energy a batterycan be expected to store and deliver over its lifetime. In someexamples, the energy throughput may be associated with an energy usageprofile of an HEV battery.

At step 206, the temperature of the catalyst is measured. At step 208,is it determined whether the catalyst is at, or above, the thresholdtemperature. In response to the answer to step 208 being yes, process200 continues to step 210. At step 210, a waiting period is initiatedbefore the process returns to step 202. In some examples, if theresponse to step 208 is yes, the process 200 ends.

If the answer to step 208 is no, process 200 continues to step 212. Atstep 212, how many heating elements to selectively operate to achievethe threshold temperature of the catalyst is determined, with theminimal impact to HEV battery throughput. In some examples, in responseto determining that the threshold temperature has been achieved, themethod further comprises deactivating at least one of the plurality ofheating elements of the after-treatment system, further reducing theimpact to HEV battery throughput reducing the charging and dischargingof the battery. After step 212, process 200 may continue to process 100as described regarding FIG. 1 above. In particular, in some examples,process 200 further comprises selectively operating one or more of theheating elements of the heating module to provide heat to the catalystbased on an operational parameter of the after-treatment system.However, notably, selectively operating one or more of the heatingelements may further be based on step 212.

In some examples, the after-treatment system includes an eCAT and acatalyst. The after-treatment system is heated until it reaches athreshold temperature, which may be the same as the most efficienttemperature of the catalyst, e.g., for a given operating condition. Insome examples, the threshold temperature may be above the most efficienttemperature of the catalyst, to allow for some cooling effects betweenending the heating of the after-treatment system and later starting anengine. In some examples, the threshold temperature may be below themost efficient temperature of the catalyst, to allow for heating fromthe engine exhaust to bring the catalyst up to its most efficienttemperature.

In some examples, selectively operating one or more heating elementscomprises operating a pulse-width modulation (PWM) switch electricallyconnected to the heating elements to modulate power from a power sourceto the heating elements of the after-treatment system. In some examples,it is step 104 that activates an eCAT to provide thermal energy to theafter-treatment system.

FIG. 3 illustrates the PWM switching of a hybrid system without theteachings of the present disclosure. Conventionally, an eCAT will berequired to perform a heat maintenance use case. To support theintermediate power levels for a ‘heat maintenance’ use case, a low power(e.g., ˜2 kW) less than the rated power (e.g., ˜4 kW) of the device maybe required. For example, as shown, the hybrid battery of the HEVplatform system will be switched on (4 kW) and off (0 kW), this is shownby line 310 in FIG. 3 . Through Pulse Width Modulation (PWM) the cyclingon and off of, for example, a 4 kW power supply generates an average 2kW power supply, as shown by line 320. This cycling of the battery willincrease the battery energy throughput, aging the battery. Additionalthroughput will detract from the available battery life, which couldotherwise have been utilized to support other system functions, andincreases the internal resistance due to the battery cycling degradingthe discharge and charge performance of the battery over time.Consequently, other system functions may be limited to ensure thebattery remains functional at the expected end of vehicle life, which iscrucial on an HEV in terms of supporting the voltage quality of the 12Vsystem. One solution to overcome these issues is to increase the batterycapacity to be durable despite the additional throughput; however, thissolution will have a dramatic increase in cost, impact the packaging ofthe battery, increase the weight and have a further effect on thecooling requirements for the HEV platform.

FIGS. 4A to 4B illustrate exemplary heating elements of a heating modulefor providing heat to a catalyst of an after-treatment system, inaccordance with at least one of the examples described herein. Withregard to FIG. 4A there is shown a heating module 410 comprising aheating element 420. Heating element 420 is controlled by a controlmodule 400, (e.g., a powertrain control module). In some examples, thecontrol module 400 controls a hybrid system 402 (e.g., a hybrid systempower source, such as a high voltage power source). In some examples,the control module 400 controls a PWM switch 404, which is in turnelectrically connected to the heating element 420. Heating module 410comprises a plurality of heating elements 420, for example, two or moreheating elements (not shown). In some examples, each of the plurality ofheating elements has the same thermal output power. In other examples,two or more of the plurality of heating elements have a differentthermal output power.

The plurality of heating elements may comprise various form factorsincluding, but not limited to, a coil type or metallic foam type. Forexample, FIG. 4B illustrates a first heating element 430 and a secondheating element 435 concentrically packaged in a disk volumearrangement. It should be understood that while two heating elements430, 435 are shown, one or more additional heating elements areconsidered to be included in this disclosure. For example, arrangementsmay have more than two heating elements (e.g., 10 heating elements). Inthe arrangement as shown in FIG. 4B, the plurality of heating elementsare spatially separated in such a way to allow thermal energy emittedfrom the heating elements to be carried away and to prevent a shortcircuit between the plurality of heating elements. This example may bereferred to as the ‘hockey puck’ embodiment. In some examples, theheating elements 430, 435 are not arranged in a ‘spiral’ configurationbut a linear (e.g., parallel heating elements), or in a polygonarrangement (e.g., with at least three straight sides and angles, andtypically five or more, such as a honey-comb). In some examples, anelectrical grid (rather than a coil) or a cone-based shape may beadopted. In some examples, each of the heating elements in the pluralityof heating elements, for example, a first heating element 430 and secondheating element are electrically connected to the first PWM switch 404and second PWM switch, respectively. In some examples, a subset or groupof the plurality of heating elements may be connected to the same PWMswitch.

FIG. 4C illustrates a concept of a heating module 410 having a unitarystructure and comprising a plurality of heating elements. In someexamples, the heating module may comprise a metallic foam 440. As shownin FIG. 4C, different sections/portions of the metallic foam 440, forexample, a first section 442, a second section 444, and a third section446 are physically joined and electrically isolated from one another.Each of the sections 442, 444, and 446 of the metallic foam 440 areelectrically connected to a separate PWM switch, for example, a firstPWM switch 404, a second PWM switch 406, and a third PWM switch 408,respectively. In some examples, each of the sections 442-446 of themetallic foam 440 are connected to the PWM switches 404-408 and may eachbe considered to be independently powered, as shown by the connectingwires 452-456. In some examples, each of the sections 442-446 of themetallic foam 440 are considered to be the heating elements of theheating module. Accordingly, each of the sections 442-446 is selectivelyactivatable. In some examples, as illustrated in FIG. 4C, each of thesections 442-446 of the metallic foam 440 may be of different formand/or size (e.g., a different surface area, and/or a different volume)relative to one another. In some examples, two or more of the sections442-446 of metallic foam 440 may be the same, or similar, form and/orsize (e.g., the same, or similar, surface area, and/or the same, orsimilar, volume).

FIGS. 5A and 5B depict exemplary results achieved due to theimplementation of the present disclosure, with respect to a hybridbattery, in accordance with at least one of the examples describedherein. In particular, FIG. 5A depicts how the internal resistance of anHEV battery increases over lifetime usage (shown as energy throughputmeasured in kWh, kilowatt-hours). At 0 kWh, the battery may beconsidered new and therefore has a normalized internal resistance of100%. Line 512 illustrates the normalized increase of internalresistance of an HEV battery as energy throughput increases in animplementation without the disclosures of the present application. Line514 illustrates the normalized increase of internal resistance of an HEVbattery as energy throughput increases in an implementation inaccordance with at least one of the examples described herein. As shown,the rate of increase of the internal resistance of the HEV batteryincreases at a faster rate for the implementation without any of theexamples as described herein. At 50 kWh of energy throughput in the HEVbattery, the increase of the internal resistance as shown by line 512 is110% and approximately 108% as shown by line 514; a delta, and thereforeimprovement, of 2%. At 200 kWh of energy throughput, however, the deltabetween lines 512 and 514 has increased to approximately 9%.

FIG. 5B depicts how the capacity of an HEV battery decreased overlifetime usage (shown as energy throughput measured in kWh). Line 522illustrates the normalized decrease of capacity of an HEV battery asenergy throughput increases in an implementation without the disclosuresof the present application. Line 524 illustrates the normalized decreaseof capacity of an HEV battery as energy throughput increases in animplementation in accordance with at least one of the examples describedherein. At 0 kWh, both lines 522 and 524 are shown at 100% normalizedcapacity, indicating that both implementations start with full expectedcapacity. As shown, the rate of decrease of the capacity of the HEVbattery increases at a faster rate for the implementation without any ofthe examples as described herein. At 50 kWh of energy throughput in theHEV battery, the decreased capacity of the HEV battery as shown by line522 is at 90% and approximately 92.5% as shown by line 524; a delta, andtherefore improvement, of 2.5%. At 200 kWh of energy throughput,however, the delta between lines 522 and 524 has increased toapproximately 7.5%.

The values of the normalized data in FIGS. 5A & 5B is largely shown forillustration purposes. It should be understood that many other variablesaffect how the battery capacity and internal resistance of an HEVbattery changes over its lifetime usage. However, these values have beengenerated with the assumption the only differences between the twoimplementations are the disclosures herein, to further illustrate theadvantages and benefits of the present disclosure. In some examples,combinations of one or more of the examples disclosed herein may furtherimprove the benefit gained as shown in FIGS. 5A & 5B.

FIG. 6 illustrates an exemplary exhaust system 600 comprising an engine610 and an after-treatment system, comprising an eCAT 620. In someexamples, the eCAT 620 comprises a catalyst 625 that is provided heat bythe methods as described herein. In some examples, and as shown in FIG.6 , there is provided an air-box 612 connected to a compressor 614 todraw air from the atmosphere. The airbox 612 and compressor 614 arefluidly connected to engine 610 and after-treatment system to transferthermal energy from a plurality of heating elements 632 disposed withinthe heating module 630 within the after-treatment system to the rest ofthe after-treatment system (e.g., to the catalyst 625). Due to thereduction in battery throughput, as illustrated in FIGS. 4A & 4B,additional devices can be added to the power net of the hybrid system.In some examples, to support local emissions regulations, additionalsystems such as an e-compressor 614 may be required. The saving inbattery throughput, due to adopting a plurality of heating elementswithin the eCAT 620, enables an existing battery to support thethroughput demands over the life of the vehicle, negating the need toincrease the capacity and therefore cost of the battery.

In some examples, there is a diesel particulate filter 640 downstream ofengine 610. A diesel particulate filter (DPF) is a filter that capturesand stores exhaust soot, coke, and/or char, collectively referred to asparticulate matter. The DPF is another form of after-treatment utilizedto reduce emissions from diesel cars. DPFs have a finite capacity, thetrapped particulate matter periodically has to be emptied or ‘burnedoff’ to regenerate the DPF, which an eCAT may also be used to assistwith. This regeneration process cleanly burns off the excess particularmatter deposited in the filter, reducing the harmful exhaust emission.In some examples, selectively operating one or more of the heatingelements of the heating module to provide heat to the catalyst may bebased on an amount of particulate matter in the after-treatment system.For example, if the amount of particular matter within theafter-treatment system is determined to be above a threshold, moreheating elements of the heating module can be selectively operated toregenerate the after-treatment system (e.g., the DPF).

In some examples, there is also provided a selective catalytic reduction(SCR) 650 system. An SCR is another emissions control technology systemthat injects a liquid-reductant agent through a special catalyst intothe exhaust stream of engines, in particular diesel engines. Thereductant source is usually automotive-grade urea, otherwise known asdiesel exhaust fluid (DEF). The DEF sets off a chemical reaction thatconverts nitrogen oxides into nitrogen, water, and low amounts of carbondioxide (CO2), which is then expelled through the vehicle tailpipe 670.The DEF may be stored in a DEF tank 660. The DEF may be distributedthrough a number of pumps and valves 662 and 664, as shown in FIG. 6 .The number of pumps and valves 662 and 664 are for illustration purposesand additional pumps and valves 662 and 664 may be located throughoutthe exhaust and/or after-treatment system. The location of the pumps andvalves 662 and 664 are similarly for illustration purposes and thelocation of the pumps and valves 662 and 664 can be different from thatshown in FIG. 6 .

In some examples, the exhaust system comprises a number of sensors 672to detect the flue gas containing oxides of nitrogen (NOx) and oxides ofsulfur (SOx), to ensure the final emissions are within a regulationamount. Euro 5 exhaust emission legislation and Euro 6 exhaust emissionlegislation, have effectively made it mandatory for DPFs, DEF, and SCRsto meet the emissions standards. However, future emission legislation,such as Euro 7, such technology alone may not be sufficient. The systemsand embodiments described herein may replace, or work in conjunctionwith DPFs, DEF, and SCRs and meet the future standards.

In some examples, the exhaust system comprises an exhaust gas recoverysystem, which is enabled by an EGR switch 680. The EGR switch 680enables some or all exhaust gas, or the thermal energy of the exhaustgas, to be recirculated through the exhaust system to further compoundthe heating effect of the heating elements 632 within the heating module630.

FIG. 7 shows a block diagram representing an electrical power controlsystem 700 for a hybrid vehicle. In the example shown in FIG. 7 , thepower control system 700 is for an exemplary mHEV system architecture,in accordance with at least one of the examples described herein. Shownin FIG. 7 is a belt-integrated starter-generator (BISG) 712, which is adevice that may apply positive torque and assist the engine in reducingthe amount of work it has to do, or, in some examples, apply negativetorque to generate electrical energy. The BISG 712 may be referred to asa motor-generator. The BISG 712 is integrated into the drive train 710,along with engine 610, clutch 716, and transmission 718. In someexamples, the BISG 712 replaces a conventional non-hybrid engine's lowvoltage (e.g., 12V) alternator. In some examples, the BISG 712 transmitstorque to the engine's crankshaft when it's operating as a hybrid drivemotor, and the crankshaft transmits torque back to the BISG 712 when itoperates as a generator, converting kinetic energy from the movingvehicle back into electricity, operating as a conventional alternator.

In some examples, the engine 610 has an exhaust system 720 comprising aneCAT 620. In some examples, the eCAT is electrically connected to aplurality of PWM switches 724. In some examples, the PWM switches 724electrically connect a plurality of heating elements 632 to the eCAT620. In the example shown in FIG. 7 , a DC-DC converter 730 iselectrically connected to a low voltage (e.g., 12V) battery and bus 740,which is configured to supply electrical power to one or more lowvoltage accessories of the HEV.

In the example shown in FIG. 7 , the power control system 700 comprisesa controller 760, e.g., an engine control module (ECM), may be inoperational communication with each of the BISG 712, the engine 714, theDC-DC converter 730, the eCAT 620, the PWM switches 724, the pluralityof heating elements 632, the low voltage battery and bus 740, the highvoltage battery and bus 750 (e.g., an HEV power system), and a pump 770.The pump 770 may be a water pump as part of the low temperature liquidcooling circuit of the hybrid system. In some examples, the pump isfluidly connected to the components of the after-treatment system totransfer unwanted thermal energy from the components, away.

The present disclosure is not limited to the set-up shown in FIG. 7 .For example, the controller 760 may be a stand-alone controller or anyother appropriate controller of the hybrid vehicle. For example, thecontroller may, at least in part, be integrated with another controllerof the vehicle. Furthermore, the controller 760 may be configured tooperationally communicate with any one or more of the vehicle componentsshown in FIG. 7 , and/or any other appropriate components of thevehicle. For example, controller 760 may be a stand-alone controllerconfigured to operationally communicate with at least one high voltageaccessory, an electric motor-generator, and an eCAT, to control theelectrical power output of the high voltage battery 750.

While the example shown in FIG. 7 exemplifies the use of the controlsystem 700 for an mHEV, it is understood that the control system 700 maybe implemented on an appropriate type of hybrid vehicle, such as aplug-in hybrid electric vehicle (PHEV), having one or more high voltagecircuit components and an eCAT 620. System 700, shown in FIG. 7 , isconfigured to supply the electrical power output of a high voltagebattery 750 of a hybrid vehicle to the eCAT 620 through the selectableoperation of the plurality of heating elements 632 via PWM switches 724,as described in the examples above and below.

FIG. 8 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein. In some examples,the after-treatment system comprises a heating module having a pluralityof heating elements. Each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system. In some examples, process 800 starts after step206 of process 200, that is to say, that process 800 is an alternativeor additional process to process 200. At step 206, the temperature ofthe catalyst has been measured (not shown). At step 208, is itdetermined whether the catalyst is at, or above, the thresholdtemperature. In response to the answer to step 208 being yes, process200 continues to step 210. At step 210, a waiting period is initiatedbefore the process returns to step 202.

In response to the answer of step 208 being no, in process 800, theprocess continues to step 802. At step 802, a time threshold to achievea threshold temperature of the catalyst is determined. For example, thesystem may be determined that the catalyst has to reach the thresholdtemperature within a certain period of time, such as under one minute,to be compliant with local regulations. In some examples, the timethreshold may be longer due to a user of the vehicle remotely initiatingone or more processes 100, 200, 800, or 900. In some examples, the timethreshold can be updated to be shorter or longer after process 800 hasbeen initiated. For example, in response to determining the user getsout of the vehicle, the time threshold can be increased. In someexamples, the time threshold can be increased based on one or morecontextual factors and/or operational parameter(s). For example, if theambient temperature is relatively high, the temperature of the catalystis high, or the time since the last engine start was recent, then thetime threshold may be increased due to the latent heat that is retainedin the after-treatment system.

At step 804, how many heating elements to operate to achieve thethreshold temperature of the catalyst within the time threshold isdetermined. For example, for a short time threshold, it may be necessaryfor all, or most, of the heating elements to be activated. For longerperiods of time, fewer heating elements may be needed to reach thethreshold temperature. In some examples, how many heating elements tooperate is further based on the minimum impact to HEV battery energythroughput (as described previously, minimizing the throughput reducesthe degradation of battery performance and aging over the HEV batterylifetime). There is a need to avoid switching between 0 kW and the ratedpower of the element to output an average power as this cycling degradesthe life of the battery. Therefore, within the combination of elements,the number of elements activated may be selected based on the minimumthroughput to meet the demanded eCAT power (i.e. use full rated power of1 or more eCAT elements). In some examples, the full rated power of oneor more eCAT elements may be used in conjunction with one or more eCATelements being switched through PWM. However, because the power ratingof the PWM switched elements is much lower than previously (i.e.,without the present teachings) the overall effect of minimizing thethroughput is achieved.

After step 804, the process continues to steps 102 and 104 of process100. That is to say that one or more of the heating elements of theheating module are selectively operated (step 102) and heat is providedto the catalyst based on an operational parameter of the after-treatmentsystem using one or more heating elements (step 104).

Alongside steps 102 and 104, in particular step 104, process 800comprises step 806. Step 806 determines, or estimates, whether thethreshold temperature of the catalyst will be met within the timethreshold. Although this step is shown as succeeding step 104, step 806may be performed in parallel with step 102 and/or step 104.

In response to the answer to step 806 being no, process 800 returns tostep 804 to re-determine how many heating elements to operate to achievethe threshold temperature of the catalyst within the time threshold. Inresponse to the answer to step 806 being yes, process 800 can continueonto step 808 and deactivate at least one of the heating elements. Forexample, if less heat provided to the catalyst would still meet the timethreshold, energy throughput in the HEV battery may be conserved bydeactivating one (or more) of the heating elements. Process 800 may alsoreturn to step 208 as shown in FIG. 8 , or the process may end.

FIG. 9 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein. In some examples,the after-treatment system comprises a heating module having a pluralityof heating elements. Each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system. Process 900 starts at step 902. At step 902, oneor more contextual factors are determined. In some examples, the one ormore contextual factors comprise at least one of an ambient temperature;a state of charge of a power source of the vehicle; a time since thelast engine start-up; or a delta temperature between the temperature ofthe after-treatment system and the ambient temperature.

At step 904, one or more of the heating elements of the heating moduleare selectively operated. In some examples, the heating elements areselected and operated based on one or more contextual factors. Forexample, heating elements may be more desirable to select based on theirpower rating or proximity to the catalyst.

At step 906, heat to the catalyst is provided based on an operationalparameter of the after-treatment system, and one or more contextualfactors. The heat is provided using one or more heating elements of theheating module. In some examples, in addition to a cold start of theafter-treatment system (e.g., an operational parameter) the ambienttemperature surrounding the after-treatment system (e.g., a contextualfactor) would help the system to better choose a combination of one ormore of the plurality of heating elements to ensure that the rightamount of heat energy is provided to the catalyst. In such examples, thecontextual factors may increase the number of one or more heatingelements selected to be operated and provide heat to the catalyst or,conversely, the contextual factors may decrease the number of heatingelements selected to be operated and provide heat to the catalyst.

FIG. 10 illustrates an example flow chart of a method of providing heatto a catalyst of an after-treatment system for a vehicle, in accordancewith at least one of the examples described herein. In some examples,the after-treatment system comprises a heating module having a pluralityof heating elements. Each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system. Process 1000 starts after process 100, 200, 800,and/or 900, as described with reference to FIGS. 1, 2, 8, and 9 above,ends. After the end of the above processes, step 1002 may follow.

At step 1002, an engine of the vehicle is started. In some examples, andas shown in process 1000, the engine of the vehicle may be started afterthe after-treatment system reaches the threshold temperature. However,it is intended to be included in this disclosure that the engine couldbe started in parallel, after, or prior to any one of the steps asdescribed with reference to processes 100, 200, 800, and 900. Theexample shown in FIG. 10 however is advantageous because it is ensuredthat the vehicle will be compliant with the local regulations on vehicleemissions prior to engine start, if the engine is started after one of,or a combination of, processes 100, 200, 800, or 900. In some examples,during a drive cycle, the after-treatment systems, as describedpreviously, could be well above the target temperature, however, thetemperature of the system could begin to decrease due to a reducedengine load (e.g., driving around town between traffic lights). In thiscase, the eCAT would be activated to maintain the temperature—known asheating maintenance—and the engine would have already been started priorto the eCAT being activated.

FIG. 11 illustrates a vehicle comprising an exemplary exhaust system, inaccordance with at least one of the examples described herein. Accordingto some examples, there is provided a vehicle 1100 comprising an exhaustsystem 600 as described with reference to FIG. 6 . In some examples, thevehicle further comprises a drive train 710 comprising a BISG 712, anengine 610, clutch 716, and transmission 718. The exhaust system 600 maycomprise an eCAT as described in any of the examples above.

In some circumstances, any incremental cost to support the plurality ofheating elements, e.g., over a single heating element, may be anintermediate cost point between a PWM-based strategy (as describedabove) and an alternate system, which may include an additional DC-DCconverter to control the eCAT load, which increases cost. Further, thesolution is advantageous in reducing battery throughput, which is aconcern with the PWM switching approach. The proposed solution wouldenable a reduction of battery throughput, which may mean the additionalDC-DC converter approach is not required. Packaging and additional DC-DCconverter into the vehicle 1100 system may not be possible and the DC-DCconverter would have significant cooling requirements. Accordingly, withthe additional throughput over the expected lifetime of the vehicle, theproposed solutions enable additional devices to be supported by the samevehicle 1100 powernet (not shown), without the need to increase thebattery capacity and therefore cost. Advantages of the presentdisclosure are clear, however, it is emphasized that the presentteachings reduce the degradation of discharge/charge performance (e.g.,through reducing the increase in internal resistance) and battery aging(i.e., helping to maintain durability) over the life of the battery ofan HEV system. The present teachings will also apply, however, to anysystem wherein a battery has high energy throughput and suffers from anincrease in internal resistance and battery aging due.

FIG. 12 illustrates a block diagram 1200 of computing module 1202, inaccordance with some embodiments of the disclosure. In some examples,computing module 1202 may be communicatively connected to a userinterface. In some examples, computing module 1202 may includeprocessing circuitry, control circuitry, and storage (e.g., RAM, ROM,hard disk, removable disk, etc.). Computing module 1202 may include aninput/output path 1206. I/O path 1206 may provide device information, orother data, over a local area network (LAN) or wide area network (WAN),and/or other content and data to control circuitry 1204, that includesprocessing circuitry 1208 and storage 1210. Control circuitry 1204 maybe used to send and receive commands, requests, signals (digital andanalog), and other suitable data using I/O path 1206. I/O path 1206 mayconnect control circuitry 404 (and specifically processing circuitry408) to one or more communications paths. In some examples, computingmodule 1202 may be an on-board computer of a vehicle, such as vehicle1100.

Control circuitry 1204 may be based on any suitable processing circuitrysuch as processing circuitry 1208. As referred to herein, processingcircuitry should be understood to mean circuitry based on one or moremicroprocessors, microcontrollers, digital signal processors,programmable logic devices, field-programmable gate arrays (FPGAs),application-specific integrated circuits (ASICs), etc., and may includea multi-core processor (e.g., dual-core, quad-core, hexa-core, or anysuitable number of cores) or supercomputer. In some examples, processingcircuitry may be distributed across multiple separate processors orprocessing units, for example, multiple of the same type of processingunits (e.g. two Intel Core i7 processors) or multiple differentprocessors (e.g., an Intel Core i5 processor and an Intel Core i7processor). In some examples, control circuitry 1204 executesinstructions for computing module 1202 stored in memory (e.g., storage1210).

Memory may be an electronic storage device provided as storage 1210,which is part of control circuitry 1204. As referred to herein, thephrase “electronic storage device” or “storage device” should beunderstood to mean any device for storing electronic data, computersoftware, or firmware, such as random-access memory, read-only memory,hard drives, solid state devices, quantum storage devices, or any othersuitable fixed or removable storage devices, and/or any combination ofthe same. Non-volatile memory may also be used (e.g., to launch aboot-up routine and other instructions). Storage 1210 may be sub-dividedinto different spaces such as kernel space and user space. Kernel spaceis a portion of memory or storage that is, e.g., reserved for running aprivileged operating system kernel, kernel extensions, and most devicedrivers. User space may be considered an area of memory or storage whereapplication software generally executes and is kept separate from kernelspace so as to not interfere with system-vital processes. Kernel modemay be considered as a mode when control circuitry 404 has permission tooperate on data in kernel space, while applications running in user modemust request control circuitry 1204 to perform tasks in kernel mode onits behalf.

Computing module 1202 may be coupled to a communications network. Thecommunication network may be one or more networks including theInternet, a mobile phone network, mobile voice or data network (e.g., a3G, 4G, 5G or LTE network), mesh network, peer-to-peer network, cablenetwork, cable reception (e.g., coaxial), microwave link, DSL reception,cable internet reception, fiber reception, over-the-air infrastructureor other types of communications network or combinations ofcommunications networks. Computing module 1202 may be coupled to asecondary communication network (e.g., Bluetooth, Near FieldCommunication, service provider proprietary networks, or wiredconnection) to the selected device for generation for playback. Pathsmay separately or together include one or more communications paths,such as a satellite path, a fiber-optic path, a cable path, a path thatsupports Internet communications, free-space connections (e.g., forbroadcast or other wireless signals), or any other suitable wired orwireless communications path or combination of such paths.

In some examples, the control circuitry 1204 is configured to carry outany of the methods as described herein. For example, storage 1210 may bea non-transitory computer-readable medium having instructions encodedthereon, to be carried out by processing circuitry 1208, which causecontrol circuitry 1204 to carry out a method to provide heat to acatalyst of an after-treatment system for a vehicle, the after-treatmentsystem comprising a heating module having a plurality of heatingelements, wherein each of the plurality of heating elements isindependently operable to provide thermal energy to the catalyst of theafter-treatment system, the method comprising: selectively operating oneor more of the heating elements of the heating module to provide heat tothe catalyst based on an operational parameter of the after-treatmentsystem.

It should be understood that the examples described above are notmutually exclusive with any of the other examples described withreference to FIGS. 1-12 . The order of the description of any examplesis not meant to identify key or essential features of the claimedsubject matter, the scope of which is defined uniquely by the claimsthat follow the detailed description. Furthermore, the claimed subjectmatter is not limited to implementations that solve any disadvantagesnoted above or in any part of this disclosure.

Other variations to the disclosed embodiments can be understood andeffected by those skilled in the art in practicing the claimeddisclosure, from a study of the drawings, the disclosure, and theappended claims. In the claims, the word “comprising” does not excludeother elements or steps, and the indefinite article “a” or “an” does notexclude a plurality. The mere fact that certain measures are recited inmutually different dependent claims does not indicate that a combinationof these measures cannot be used to advantage. Any reference signs inthe claims should not be construed as limiting the scope.

This disclosure is made to illustrate the general principles of thesystems and processes discussed above and are intended to beillustrative rather than limiting. More generally, the above disclosureis meant to be exemplary and not limiting and the scope of thedisclosure is best determined by reference to the appended claims. Inother words, only the claims that follow are meant to set bounds as towhat the present disclosure includes.

While the present disclosure is described with reference to particularexample applications, it shall be appreciated that the disclosure is notlimited thereto. It will be apparent to those skilled in the art thatvarious modifications and improvements may be made without departingfrom the scope and spirit of the present disclosure. Those skilled inthe art would appreciate that the actions of the processes discussedherein may be omitted, modified, combined, and/or rearranged, and anyadditional actions may be performed without departing from the scope ofthe disclosure.

Any system feature as described herein may also be provided as a methodfeature and vice versa. As used herein, means plus function features maybe expressed alternatively in terms of their corresponding structure. Itshall be further appreciated that the systems and/or methods describedabove may be applied to, or used in accordance with, other systemsand/or methods.

Any feature in one aspect may be applied to other aspects, in anyappropriate combination. In particular, method aspects may be applied tosystem aspects, and vice versa. Furthermore, any, some, and/or allfeatures in one aspect can be applied to any, some, and/or all featuresin any other aspect, in any appropriate combination. It should also beappreciated that particular combinations of the various featuresdescribed and defined in any aspect can be implemented and/or suppliedand/or used independently.

1-15. (canceled)
 16. A method of controlling an after-treatment systemfor a vehicle, the after-treatment system comprising a heating modulehaving a plurality of heating elements, wherein each of the plurality ofheating elements is independently operable to provide thermal energy toa catalyst of the after-treatment system, the method comprising:determining how many of the plurality of heating elements to selectivelyoperate based on an operational parameter of the after-treatment system;and in response to the determination, selectively operating one or moreof the heating elements of the heating module.
 17. The method of claim16, further comprising: in response to the determination, selectivelyoperating one or more of the heating elements of the heating module tolimit battery throughput.
 18. The method of claim 16, furthercomprising: in response to the determination, selectively operating oneor more of the heating elements of the heating module to provide heat tothe catalyst until a threshold temperature of the catalyst is achieved.19. The method of claim 18, wherein the threshold temperature of thecatalyst is achieved within a time threshold.
 20. The method of claim18, further comprising: in response to determining that the thresholdtemperature has been achieved, deactivating one of the plurality ofheating elements of the after-treatment system.
 21. The method of claim16, wherein the operational parameter comprises at least one of: anengine temperature; an exhaust gas flow-rate through the after-treatmentsystem; a maximum thermal energy output from the plurality of heatingelements; temperature of the catalyst; battery throughput; or an amountof particulate matter in the after-treatment system.
 22. The method ofclaim 16, further comprising determining one or more contextual factors,wherein the one or more contextual factors comprise at least one of: anambient temperature; a state of charge of a power source of the vehicle;a time since a last engine start-up; or a delta temperature between thetemperature of the after-treatment system and the ambient temperature;and wherein at least one of the plurality of heating elements of theheating module is selectively operated to provide heat to the catalystbased on one or more of the contextual factors.
 23. The method of claim18, further comprising: starting an engine of the vehicle after theafter-treatment system reaches the threshold temperature.
 24. The methodof claim 16, further comprising: controlling at least one of theplurality of heating elements with at least one pulse-width modulationswitch.
 25. An after-treatment system comprising: a heating modulecomprising a plurality of heating elements, wherein each of theplurality of heating elements is independently activatable to providethermal energy to a catalyst of the after-treatment system; and acontrol module to determine how many of the plurality of heatingelements to selectively operate based on an operational parameter of theafter-treatment system.
 26. The after-treatment system of claim 25,wherein the heating module comprises a metallic foam, the metallic foamcomprising: a first section; and a second section, wherein the firstsection and second section are physically joined and electricallyisolated.
 27. The after-treatment system of claim 26, wherein each ofthe first and second seconds are electrically connected to a separatepulse-width modulation, PWM, switch.
 28. The after-treatment system ofclaim 25, wherein the first and second section have different physicalcharacteristics, the characteristics being at least one of: differentsurface area; different volume; or different structure.
 29. A vehiclecomprising the after-treatment system of claim
 25. 30. A non-transitorycomputer-readable medium having instructions encoded thereon forcarrying out a method to control an after-treatment system of a vehicle,the after-treatment system comprising a heating module having aplurality of heating elements, wherein each of the plurality of heatingelements is independently operable to provide thermal energy to acatalyst of the after-treatment system, the method comprising:determining how many of the plurality of heating elements to selectivelyoperate based on an operational parameter of the after-treatment system.